The IEEE 802.21 standard includes mechanisms and procedures that aid in the execution and management of inter-system handovers. In particular, IEEE 802.21 defines a media independent handover (MIH) function (MIHF) which resides in communications entities of several wireless systems capable of supporting inter-system handover. For example, FIG. 1 shows an example of network architecture for wireless systems capable of supporting inter-system handover. These underlying technologies may include for example 3GPP, 3GPP2 and IEEE-based networks such as IEEE 802.xx, code division multiple access (CDMA) 2000; universal mobile telephone system (UMTS), GSM, long term evolution (LTE) or any other wireless communication system including future wireless communication systems not yet developed.
MIH functions can be implemented in any wireless communication system. The prior art has suggested enhancements regarding the use of several messages, including an MIH_Capability_Discover_Request/Confirm message. Such enhancements include modifications to message parameters so that MIH capable nodes can discover the capabilities of other MIH enabled peers in an efficient manner.
The modifications to the message parameters enables a single MIH_Capability_Discover message to be used to discover all the important capabilities of a peer node, such as the number and type of supported links and the link events pertaining to specific link types as opposed to the previous method where one such message had to be sent for every link type that is supported at a remote end.
Although proposed structures may provide an efficient way of discovering link-related capabilities and the type of transport supported, such structures do not facilitate determination of other important the capabilities of these links. Accordingly, a vast improvement in the capability discovery is still greatly needed.